The effects of perceived social support on quality of life in patients awaiting coronary artery bypass grafting and their partners: testing dyadic dynamics using the Actor-Partner Interdependence Model.

Patients awaiting coronary artery bypass grafting (CABG) need support from their partners or family caregivers to manage their self care successfully and to maximise quality of life. Partners need social support to help overcome the stressful tasks of an unexpected caregiving role. It is not known whether the individual's perceived social support contributes to their own, as well as their partner's quality of life. The aims of this study were to assess differences in social support and quality of life in patients and partners awaiting CABG, and to examine whether patients' and partners' perceived social support predicted their own, as well as their partner's quality of life before CABG. This cross-sectional study recruited 84 dyads (patients 84% males, aged 64.5 years and partners 94% females, aged 61.05 years). Perceived social support was assessed using the Medical Outcomes Study Social Support survey, with sub-scales for informational/emotional support, affectionate support, tangible support and positive social interaction. Quality of life was assessed using the Short-Form 12 Health Survey. Dyadic data were analysed using the Actor-Partner Interdependence Model, with distinguishable dyad regression. Results revealed the patients' informational/emotional support exhibited an actor effect on their own mental health (ß = 0.19, p = 0.001); indicating those with low informational/emotional support had poorer mental health. There was a partner effect of the patients' informational/emotional support on their partner's mental health (ß = 0.14, p = 0.024), indicating the patients' informational/emotional support was associated with the partner's mental health. None of the other types of social support exhibited an actor effect or a partner effect on the patient's or the partner's mental or physical health. More research into the relationship between social support and mental health is needed to help inform the design of interventions that target the dyad.